1. Field of the Invention
The present invention relates to a spark plug, e.g., a swirl chamber spark plug used for stationary gas engines.
2. Description of the Related Art
Known swirl chamber spark plugs are primarily used in large gas engines. In these spark plugs, the service life of the spark plug is a decisive economic and technical factor, since the spark plugs themselves and their replacements are relatively expensive. In known swirl chamber spark plugs, the precious metal surfaces of the electrodes, on which the sparks are produced, are designed to be as large as possible. A large amount of costly precious metal must be used in this case, since it is not possible to take advantage of the material thickness. Furthermore, it is not possible to readjust the distances of the electrodes in known swirl chamber spark plugs, since the cap that forms or closes the swirl chamber does not allow access to the electrodes. FIG. 1 shows a swirl chamber spark plug 30 in a section perpendicular to the longitudinal axis. A center electrode 3 and a ground electrode 4 are visible. Four spark surfaces 31 are formed on each center electrode 3 and ground electrode 4. Spark surfaces 31 are situated on small precious metal plates. In known swirl chamber spark plug 30, the distance between spark surfaces 31 is neither settable nor readjustable.